The present invention relates to an anti-friction, recirculating ball bearing assembly of minimum thickness and more particularly to such an assembly employed within a mast unit for fork lift trucks.
It is common practice to employ bearing assemblies of different configurations for arrangement between the relatively movable upright sections of a mast unit or between other elongated elements intended for movement relative to each other in generally closely spaced apart relation. For example, U.S. Pat. No. 3,061,046 discloses the use of endless roller chains as anti-friction means between relatively movable mast sections.
Generally, it is desirable to employ anti-friction type bearings in order to facilitate relative movement between the upright sections of the mast unit while minimizing wear and reducing undesirable noise. However, at the same time, it is also important to provide an anti-friction bearing assembly of minimum thickness in order to permit installation of the bearing assemblies between the nested beams of the various upright sections which are commonly arranged in closely spaced apart pairs.
The general use and construction of anti-friction, recirculating ball bearing assemblies is also well demonstrated in the prior art by a great number of references. Such an antifriction, recirculating ball bearing assembly contemplated as having a generally reduced thickness may be seen, for example, in U.S. Pat. Nos. 3,767,276 and 3,843,215. However, these bearing assemblies are specifically configured for use in conjunction with a circular shaft movable within a cylindrical sleeve.